Differences in Vocabulary Knowledge as a Function of Children's Oral Comprehension Performance in Greek: A Cross-Sectional Developmental Study

The present cross-sectional developmental study examined differences in vocabulary knowledge as a function of children's oral comprehension skill and age. Participants (174 children, aged 5.5, 7.5, and 9.5 years) were presented with oral stories in Greek, accompanied by questions tapping higher-order comprehension skills (generation of necessary and elaborative inferences, simile comprehension, and comprehension control). Children performing at the highest and the lowest 25% of every age level were identified as skilled and less-skilled oral comprehenders, respectively (5.5. years: 14 vs. 17, 7.5 years: 15 vs. 15, and 9.5 years: 15 vs. 19, less-skilled vs. skilled comprehenders). Participants were assessed with a receptive vocabulary task and with short-term and working memory tasks. In line with our hypotheses, the effect of comprehension skill on vocabulary knowledge increased in our eldest group, even when we controlled for memory effects. Our findings contribute to the discussion of advantages observed in vocabulary growth for skilled comprehenders, attributed to a significant extent to their early linguistic experiences and oral language skills rather than their intellectual and learning potential. We point at the additive value of identifying comprehension skill groups based on oral measures, allowing for the evaluation of higher-order text processing skills from the critical preschool years.